At the beginning of the 20th century, the water system, which is still essentially functioning today, was established in the early 20th century to improve the outflow for the Oderbruch, which still suffers from wetness that does not run off after cultivation, in addition to securing shipping between Berlin and Szczecin all year round and optimizing the agricultural situation created. The previously meandering Stromoder was relocated to the eastern edge of the valley, the oxbow lakes of the Oder and Welse remaining on the western edge were connected with a few openings to the Hohensaaten-Friedrichsthaler waterway, which is directly connected to the West or the Baltic Sea without locks. Between the Hohensaaten-Friedrichsthaler Wasserstraße in the west and the Stromoder in the east, several were built based on the Dutch model Polders. Wet polders were created near Criewen and Schwedt, which are flooded in autumn after the inlet and outlet structures have been opened according to the water level of the Oder. In the winter half-year, large parts of this wet polder (4,720 hectares) are then under water for a long time.
In the spring, the water initially flows off through the outlet structures according to the gradient, and finally the remaining remainder is pumped out, which is costly and energy-intensive, first the inlet and later also the outlet structures are closed, so that the water level in the polder is sometimes significantly lower than the water level of the Electricity or falls. This gives the farmers the opportunity to use the meadows and pastures as early as May.
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- Schwedt pumping station
Problematic water management
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- Hydraulic engineering installation at the Fiddichower Polder (10)
From an ecological point of view, this water management from the 1930s poses a major problem because many communities in the floodplain that have established themselves there in winter and spring suddenly lose their habitat when the polders are drained. In particular, the birds that started their breeding business on higher areas in the polder, protected from the surrounding water, suddenly sit with their clutches on dry land, which then quickly become prey for the predatory mammals. For a floodplain national park this is an untenable situation.
After all, at the constant insistence of the National Park Association, the national park administration stopped pumping every year at least in the Fiddichow Polder (10) in 2015. However, the inlet and outlet structures are still closed in spring. However, they should remain open all year round, as a scientific feasibility study commissioned by the Brandenburg government itself demands. That is the next goal that the National Park Association wants to achieve from the National Park Administration. In addition, in the other large wet polder, the Criewen Schwedter Polder (A/B), the inlet and outlet structures should be closed at the earliest on 31 May of each year. This is also a requirement from the scientific feasibility study.
Economic agriculture and wilderness development in conflict
If 50 percent of the national park is to develop into a wilderness according to the current legal situation, the water should be able to flow in and out unhindered, depending on the current status of the Oder river. For the agricultural areas that should continue to be cultivated extensively (Zone II), a certain (low!) Water level must be guaranteed during the vegetation period so that economic agriculture can still be practiced. This is comparatively easy for the Fiddichower Polder (10), which is to become a completely wilderness area, and the Friedrichsthaler Polder (5/6), which is to become predominantly Zone II area. For the Criewen Schwedter Polder (A / B), in which Zone I and Zone II areas are closely interlinked, it is likely to be very difficult to create water conditions that do justice to agriculture and wilderness development.
Hydraulic maintenance measures
The hydraulic maintenance measures on the federal waterways, in particular the Stromoder and the Hohensaaten-Friedrichsthaler waterways, are also important. Here, after the so-called flood of the century in 1997, all dykes were lavishly raised and widened, groynes were rebuilt and stone embankments were laid. All inlet and outlet structures were renovated or even rebuilt. The hydraulic engineering systems have now all been perfected again in accordance with the current standards. It is doubtful whether this severe intervention in Germany’s only floodplain national park was sensible and necessary. Because of the official reason “flood protection”, no counter-speech was allowed. In the future, the maintenance measures will be about finding forms in discussions with the Federal Waterway Administration that allow the use of the waterways as a large shipping route and yet interfere with the natural balance as little as possible, as it should be for a national park. There is still a lot of (coöperation) work to be done by everyone involved.
